A roll film negative. On board the submarine Sealion (1959) towards the end of a long refit at Portsmouth. The photographer is in the gyro compass room between 65 and 68 stations below the main flat, looking towards the aft starboard corner showing the periscope heated windows dual control unit above the gyro compass electrical circuits junction box 10 on the starboard side on the left. Against the aft bulkhead are the ship's speed retransmission unit with a Bell's Scotch Whisky ashtray on it and an inverter heater unit below. A desk top is in the foreground.